APT: A Practical Tunneling Architecture for Routing Scalability

APT: A Practical Tunneling Architecture for Routing Scalability

Dan Jen (Center for Naval Analyses, USA), Michael Meisel (ThousandEyes, USA), Daniel Massey (Colorado State University, USA), Lan Wang (The University of Memphis, USA), Beichuan Zhang (The University of Arizona, USA) and Lixia Zhang (University of California, Los Angeles, USA)
Copyright: © 2014 |Pages: 23
DOI: 10.4018/978-1-4666-4305-5.ch004
OnDemand PDF Download:


The global routing system has seen a rapid increase in table size and routing changes in recent years, mostly driven by the growth of edge networks. This growth reflects two major limitations in the current architecture: (a) the conflict between provider-based addressing and edge networks’ need for multihoming, and (b) flat routing’s inability to provide isolation from edge dynamics. In order to address these limitations, we propose A Practical Tunneling Architecture (APT), a routing architecture that enables the Internet routing system to scale independently from edge growth. APT partitions the Internet address space in two, one for the transit core and one for edge networks, allowing edge addresses to be removed from the routing table in the transit core. Packets between edge networks are tunneled through the transit core. In order to automatically tunnel the packets, APT provides a mapping service between edge addresses and the addresses of their transit-core attachment points. We conducted an extensive performance evaluation of APT using trace data collected from routers at two major service providers. Our results show that APT can tunnel packets through the transit core by incurring extra delay on up to 0.8% of all packets at the cost of introducing only one or a few new or repurposed devices per AS.
Chapter Preview


Since APT is a realization of the Map & Encap scheme, we begin with an explanation of how Map & Encap works.

There are two types of networks in the Internet: transit networks whose business role is to provide packet transport services for other networks, and edge networks that only function as originators or sinks of IP packets. As a rule of thumb, if the network’s AS number appears in the middle of any AS path in a BGP (Rekhter et al., 2006) route today, it is considered as a transit network; otherwise it is considered as an edge network. Usually Internet Service Providers (ISPs) are transit networks and end-user sites are edge networks (e.g., corporate networks and university campus networks). The IP addresses used by transit networks are called transit addresses and the IP addresses used by edge networks are called edge addresses. The corresponding IP prefixes are called transit prefixes and edge prefixes.

Complete Chapter List

Search this Book: